ELECTROMAGNETIC INTERFERENCE (EMI) FROM RADIO WAVE
SOURCES
Powered scooters may be susceptible to electromagnetic interference (EMI), which is interfering
electromagnetic energy (EM) emitted from sources such as radio stations, TV stations, amateur radio (HAM)
transmitters, two-way radios, and cellular phones. The interference (from radio wave sources) can cause the
powered scooter to release its brakes, move by itself, or move in unintended directions. It can also permanently
damage the powered scooter’s control system. The intensity of the interfering EM energy can be measured in
volts per meter (V/m). Each powered scooter can resist EMI up to a certain intensity level”. The higher the
immunity level the greater the protection. At this time, current technology is capable of achieving at least a
20 V/m immunity level, which would provide useful protection from the more common sources of radiated EMI.
This powered scooter model as shipped, with no further modification, has an immunity level of 20 V/m without
any accessories.
There are a number of sources of relatively intense electromagnetic fields in the everyday environment. Some of
these sources are obvious and easy to avoid. Others are not apparent and exposure is unavoidable. However, we
believe that by following the warning listed below, your risk to EMI will be minimized.
The sources of radiated EMI can be broadly classified into three types:
1. Hand-held portable transceivers ( transmitter-receivers with the antenna mounted directly on the
transmitting unit). Examples include: citizens band (CB) or hand held radios,(security, fire, and police transceivers),
cellular telephones and other personal communication devices.
2. Medium-range mobile transceivers, such as those used in police cars, fire trucks, ambulances and taxis
usually have the antenna mounted on the outside of the scooter.
3. Long-range transmitters and transceivers, such as commercial broadcast transmitters (radio and TV
broadcast antenna towers) and amateur (HAM) radios.
NOTE: some cellular telephones transmit a signal while they are ON, even though they are not being used.